FR3058664B1 - PERCUSSION APPARATUS - Google Patents

Abstract

This percussion apparatus (2) comprises a body (3); a tool (7) having a mounting portion (8) slidably mounted in the body (3); and a striking piston (6) mounted alternately movable in the body (3) and configured to strike the mounting portion (8). The mounting portion (8) of the tool (7) has an annular retaining rib (24) having a first bearing surface configured to cooperate with a first abutment surface provided on the body (3) to limit the movement of movement of the tool (7) towards the striking piston (6), and a second bearing surface opposite to the first bearing surface and configured to cooperate with a second abutment surface provided on the body ( 3) so as to limit the movement of movement of the tool (7) away from the striking piston (6) and to retain the mounting portion (8) of the tool (7) in the body (3). ).

Description

The present invention relates to a percussion apparatus, and more particularly to a percussion apparatus powered by a fluid under pressure.

Percussion devices driven by a fluid under pressure, also called breakers, are very powerful devices intended to break rocks. Such percussion apparatus can be used for many applications, including creating foundations, reducing blocks after firing, digging tunnels or galleries, and so on.

A percussion apparatus is more particularly intended to be installed at the end of the arm of a hydraulic excavator which will serve as a carrier and which will provide the hydraulic energy necessary for the operation of the percussion apparatus and the thrust required to maintain the recoil effort created by the operation of the percussion apparatus.

A percussion apparatus creates shock waves generated by the impact of a striking piston thrown against a tool in contact with the rock to be broken. This tool is the wear part intended to transmit the shock waves that will fracture the rock. This tool must also withstand the rotational torque created by the terrain when a chisel type tool is used and the tool engages in a rock fault. Finally, for practical reasons, this tool must be mechanically held inside the percussion device during the movements of the latter or during the vacuum strikes for lack of support.

EP0575270 discloses a device for holding the tool in the body of the percussion apparatus. Such a holding device comprises in particular two retaining keys configured to cooperate each with an abutment face defined by a respective transverse notch provided on the tool. Such a holding device ensures an effective and reliable maintenance of the tool for the majority of applications for a percussion device.

However, for very difficult applications, such as digging tunnels where the environment is very aggressive, the contact surfaces between the tool and the retaining keys are too limited to avoid rapid wear of the tool and the keys. restraint or seizures that could create cracks in the body or tool.

The present invention aims to remedy all or part of these disadvantages.

The technical problem underlying the invention consists in particular in providing a percussion apparatus which is of simple structure, while ensuring an efficient and reliable operation of the percussion apparatus including for difficult applications. For this purpose, the present invention relates to a percussion apparatus, comprising at least: a body comprising a first body part and a second body part, a tool comprising a mounting part slidably mounted in the second body part, the mounting part being provided with a striking surface; - a striking piston mounted alternately movable in the first body part, and configured to strike the striking surface of the mounting part, characterized in that the the tool mounting portion comprises an annular retaining rib having a first bearing surface configured to cooperate with a first abutment surface provided in the second body portion so as to limit the travel of movement of the tool to the piston, and a second bearing surface opposite the first bearing surface and configured to cooperate with a second abutment surface provided for in the second body portion so as to limit the movement of movement of the tool away from the striking piston and to retain the mounting portion of the tool in the second body portion.

Such a configuration of the tool, and in particular the presence of the annular retaining rib, provides important contact surfaces between the tool and the body of the apparatus, unlike the apparatus of the prior art where these surfaces of contact were limited to the radii of curvature of the retaining keys and the radii of curvature of the abutment faces defined by the transverse notches provided on the tool.

Therefore, the percussion apparatus according to the present invention greatly limits the wear of the tool and the body of the apparatus, and the risk of seizure of the percussion apparatus, and thus has a high reliability. The percussion apparatus may further have one or more of the following features, taken alone or in combination.

According to one embodiment of the invention, at least one, and for example each, of the first and second bearing surfaces is annular. These arrangements further increase the contact surfaces between the tool and the body of the percussion apparatus, and thus the reliability of the percussion apparatus.

According to one embodiment of the invention, at least one, and for example each, of the first and second abutment surfaces is annular.

According to one embodiment of the invention, the striking piston and the tool extend substantially coaxially.

According to one embodiment of the invention, the first body portion and the second body portion respectively comprise a piston bore and a tool bore.

According to one embodiment of the invention, the first bearing surface converges towards the striking piston, and the second bearing surface converges on the opposite side of the striking piston.

According to one embodiment of the invention, the percussion apparatus comprises a first guide member and a second guide member mounted in the second body portion, and configured to slidably guide the mounting portion of the tool, the first and second guide members being disposed on either side of the annular retaining rib.

According to one embodiment of the invention, each of the first and second guide elements is formed by a guide sleeve.

According to one embodiment of the invention, the first and second guide elements are mounted in the tool bore. Thus, the first and second guide members are more particularly configured to slidably guide the mounting portion of the tool into the tool bore.

According to one embodiment of the invention, the second guide member is removably mounted in the tool bore.

According to one embodiment of the invention, the tool mounting portion comprises a first guided portion and a second guided portion disposed on either side of the annular retaining rib and configured to cooperate respectively with the first and second guide elements.

According to one embodiment of the invention, each of the first and second guide members comprises a central bore through which the tool mounting portion extends, and for example one of the first and second guided portions of the tool. the mounting part.

According to one embodiment of the invention, the second abutment surface is provided on the second guide element.

According to one embodiment of the invention, the percussion apparatus further comprises at least one holding element configured to hold the second guide element in the second body part.

According to one embodiment of the invention, the at least one holding element comprises at least one retaining key. The at least one retaining key extends for example through a through bore provided on the second body portion and a retaining slot provided on the second guide member.

According to one embodiment of the invention, the percussion apparatus comprises two retaining keys extending through two retaining slots provided on the second guide element and diametrically opposed.

According to one embodiment of the invention, the at least one holding element is removably fastened, for example by screwing, to an end face of the second body part, and comprises a through bore intended for the passage of the tool.

According to one embodiment of the invention, the mounting portion of the tool and at least one of the first and second guide members are configured to rotatably immobilize the mounting portion relative to the second body portion.

According to one embodiment of the invention, the central bore of at least one of the first and second guide elements has a non-circular cross section.

According to one embodiment of the invention, the mounting portion of the tool comprises at least one flat configured to cooperate with one of the first and second guide elements.

According to one embodiment of the invention, the percussion apparatus comprises an abutment ring mounted in the second body portion, the first abutment surface being provided on the abutment ring.

According to one embodiment of the invention, the stop ring is disposed between the first and second guide elements.

According to one embodiment of the invention, the percussion apparatus further comprises a striking chamber configured to be pressurized and delimited at least in part by the striking piston and the mounting portion of the tool, and a sealing member configured to seal the striking chamber. These arrangements make it possible to constantly generate a thrust force on the mounting portion of the tool, and in particular on the striking surface of the tool, and thus to urge the tool away from its theoretical position of impact. Therefore, if the operator does not exert, with the aid of the carrier, a minimum thrust on the tool to counteract the thrust force exerted on the latter, the striking piston will not be able to strike the tool. Thus, the percussion apparatus according to the present invention makes it possible to limit the idling strokes on the tool.

According to one embodiment of the invention, the striking chamber and the sealing element are configured so as to urge the tool away from its theoretical strike position, and more particularly to generate a thrust force on the mounting portion of the tool so as to urge the tool away from its theoretical position of impact.

According to one embodiment of the invention, the striking chamber is delimited at least in part by the striking surface of the mounting portion.

According to one embodiment of the invention, the sealing element is disposed between the second body portion and the mounting portion of the tool.

According to one embodiment of the invention, the sealing element is fixed on the second body portion and is configured to cooperate with the mounting portion of the tool, and for example with a portion of the mounting portion. disposed between the first guided portion and the annular retaining rib.

According to one embodiment of the invention, the sealing element is a toric or lip seal.

According to one embodiment of the invention, the sealing element is fixed in an annular groove provided on the second body part.

According to one embodiment of the invention, the sealing element is disposed between the first guide element and the annular retaining rib.

According to one embodiment of the invention, the sealing element is disposed between the first guide element and the abutment ring.

The present invention further relates to a percussion tool, comprising a mounting portion provided with a striking surface to be impacted by a striking piston of the percussion apparatus, the mounting portion being configured to be mounted slider in a body of the percussion apparatus, characterized in that the tool mounting portion comprises an annular retaining rib having a first bearing surface configured to cooperate with a first abutment surface provided in the body of the the percussion apparatus so as to limit, under use conditions, the movement of movement of the tool towards the striking piston, and a second bearing surface opposite to the first bearing surface and configured to cooperate with a second abutment surface provided in the body of the percussion apparatus so as to limit, under use conditions, the movement of movement of the tool to the opposite of the striking piston and to retain the mounting portion of the tool in the body of the percussion apparatus.

In any case the invention will be better understood with the aid of the description which follows with reference to the appended diagrammatic drawings showing, by way of non-limiting examples, several embodiments of this percussion apparatus.

Figure 1 is a schematic longitudinal sectional view of a percussion apparatus according to a first embodiment of the invention.

Figure 2 is a partial longitudinal sectional view of the percussion apparatus of Figure 1.

Figure 3 is a side view of a tool of the percussion apparatus of Figure 1.

Figure 4 is a sectional view along the line IV-IV of Figure 3.

Figure 5 is a partial longitudinal sectional view of a percussion apparatus according to a second embodiment of the invention.

Figure 6 is a partial longitudinal sectional view of the percussion apparatus according to a third embodiment of the invention.

Figure 7 is a partial longitudinal sectional view of the percussion apparatus according to a fourth embodiment of the invention. The percussion apparatus 2, shown in Figures 1 to 3 and also called hydraulic breaker, comprises a body 3 having a first body portion 3.1 and a second body portion 3.2 which respectively comprise a piston bore 4 and a tool bore 5. The piston bore 4 and the tool bore 5 advantageously extend coaxially. The percussion apparatus 2 also comprises a step piston 6 stepped alternately sliding in the piston bore 4, and a tool 7 having a mounting portion 8 slidably mounted in the tool bore 5 and provided with A striking surface 9. During each operating cycle of the percussion apparatus 2, the striking piston 6 is intended to strike against the striking surface 9 of the tool 7. It should be noted that that the piston bore 4 and the tool bore 5 can be directly formed in the body 3 or be formed in inserts in the body 3. The percussion apparatus 2 further comprises a first guide member 11 and a second guide member 12 mounted in the second body portion 3.2, and configured to slidably guide the mounting portion 8 of the tool 7 into the tool bore 5. According to the embodiment shown in the figures 1 to 3, the first and second guiding elements 11, 12 are formed by two guide bushes, and are mounted coaxially in the tool bore 5. Advantageously, the first and second guide elements 11, 12 respectively comprise two central bores 13, 14 through which extends the mounting portion 8 of the tool 7, and two guide surfaces 15, 16 which are configured to cooperate with the mounting portion 8 of the tool 7.

Advantageously, the second guide element 12 is removably mounted in the tool bore 5. For this purpose, according to the embodiment shown in FIGS. 1 to 3, the percussion apparatus 2 comprises two holding elements 17, such as retaining keys, configured to hold the second guide member 12 in the tool bore 5. Each holding member 17 extends for example through a respective through bore 18 provided on the second portion of body 3.2 and a respective holding notch 19 provided on the second guide member 12. Each holding member 17 may for example have a circular or oblong cross section. The percussion apparatus 2 also comprises an abutment ring 21 mounted in the second body portion 3.2 and extending coaxially with the first and second guide members 11, 12. The stop ring 21 is more particularly arranged between the first and second and second guide members 11, 12, and is provided with a first abutment surface 22 which is preferably annular. The percussion apparatus 2 further comprises a second abutment surface 23 which is advantageously annular and which is provided, according to the embodiment shown in FIGS. 1 to 3, directly on the second guide element 12.

As shown more particularly in Figure 3, the mounting portion 8 of the tool 7 more particularly comprises an annular retaining rib 24, and a first and a second guided portions 25, 26 disposed on either side of the rib. retaining ring 24 and configured to cooperate respectively with the first and second guide members 11,12.

The annular retaining rib 24 advantageously comprises a first bearing surface 24.1 configured to cooperate with the first abutment surface 22 provided on the abutment ring 21 so as to limit the movement of movement of the tool 7 towards the striking piston. 6, and a second bearing surface 24.2 opposite the first bearing surface 24.1 and configured to cooperate with the second abutment surface 23 provided on the second guide element 12 so as to limit the movement of movement of the tool 7 opposite the striking piston 6 and to retain the mounting portion 8 of the tool 7 in the second body portion 3.2.

Advantageously, each of the first and second bearing surfaces 24.1, 24.2 is annular, and each of the first and second abutment surfaces 22, 23 is annular.

According to the embodiment shown in FIGS. 1 to 3, the first bearing surface 24.1 converges towards the striking piston 6, the second bearing surface 24.2 converges on the opposite side of the striking piston 6, and the rib annular retainer 24 further comprises a cylindrical intermediate surface 24.3 connecting the first and second bearing surfaces 24.1, 24.2.

Advantageously, the mounting portion 8 of the tool 7 and at least one of the first and second guide elements 11, 12 are configured to immobilize in rotation the mounting portion 8 relative to the second body portion 3.2. According to the embodiment shown in Figures 1 to 3, the first guided portion 25 comprises two diametrically opposite flats Y1, and the central bore 13 of the first guide member 11 has a cross section substantially complementary to the cross section of the first guided portion 25.

FIG. 5 represents a percussion apparatus 2 according to a second embodiment which differs from that represented in FIGS. 1 to 3 essentially in that it comprises a holding element 28 removably fixed, for example by screwing, to a end face 29 of the second body portion 3.2, so as to retain the second guide members 12 in the tool bore 5. The holding member 28 advantageously has a through bore 31 for the passage of the 7. According to such an embodiment of the invention, the holding element 28 has an abutment surface 32 against which the second guide element 12 is able to bear.

FIG. 6 shows a percussion apparatus 2 according to a third embodiment which differs from that shown in FIG. 5 essentially in that it comprises an intermediate guide element 33 arranged between the abutment ring 21 and the first guide element 11.

FIG. 7 shows a percussion apparatus 2 according to a third embodiment which differs from that shown in FIGS. 1 to 3 essentially in that it comprises a sealing element 34, such as an O-ring seal or lip seal configured to seal a striking chamber 35 at least partially defined by the striking piston 6 and the first guided portion 25 of the tool 7, the striking chamber 35 being configured to be pressurized. The sealing element 34 is for example fixed in an annular groove provided on the second body portion 3.2 between the first guide member 11 and the stop ring 21, and is configured to cooperate with the mounting portion 8 of the 7, and for example with a portion of the mounting portion 8 disposed between the first guided portion 25 and the annular retaining rib 24. The presence of such a sealing member 34 can generate a thrust force F , oriented axially opposite the striking piston 6, on the mounting portion 8 of the tool 7, and in particular on the striking surface 9 of the tool 8, and thus to urge the tool 8 at a distance of its theoretical position of impact. Therefore, if the operator does not exert, with the aid of the carrier on which is fixed the percussion apparatus 2, a minimum thrust on the tool 8 to counteract the thrust force F exerted on the latter, the striking piston 6 can not come to hit the tool 8. Thus, the percussion apparatus 2 according to the present invention allows to limit the empty strikes on the tool 8.

According to an alternative embodiment not shown in the figures, the first abutment surface 22 could be directly provided on the second body portion 3.2 or be provided on the first guide element 11, and the second abutment surface 23 could be provided on an abutment member separate from the second guide element 12 and also mounted in the tool bore 5.

As goes without saying, the invention is not limited to the embodiments of this percussion apparatus, described above as examples, it encompasses all the variants.

Claims (7)

A percussion apparatus (2), comprising at least: - a body (3) comprising a first body part (3.1) and a second body part (3.2), - a tool (7) having a mounting part ( 8) slidably mounted in the second body portion (3.2), the mounting portion (8) being provided with a striking surface (9), and - a striking piston (6) mounted alternatively movable in the first body portion (3.1), and configured to strike the striking surface (9) of its mounting portion (8), the mounting portion (8) of the tool (7) having an annular retaining rib (24). ) having a first bearing surface (24.1) configured to cooperate with a first abutment surface (22) provided in the second body portion (3.2) so as to limit the travel of movement of the tool (7) towards the striking piston (6), and a second bearing surface (24.2) opposite to its first bearing surface (24.1) and configured to coo with a second abutment surface (23) provided in the second body portion (3.2) so as to limit the displacement of the tool (7) away from the striking piston (6) and to retain the mounting portion (8) of the tool (7) in the second body portion (3.2), characterized in that the percussion apparatus (2) further comprises: - a first guide member (11) and a second guide element (12) mounted in its second body portion (3.2), and configured to slidably guide the mounting portion (8) of the tool (7), the first and second guide members (11, 12); ) being disposed on either side of its annular retaining rib (24), and - an abutment ring (21) mounted in the second body portion (3.2) and disposed between the first and second guide elements (11). 12), the first abutment surface (22) being provided on the abutment ring (21) and the second abutment surface (23) is provided on the second guide member (12). The percussion apparatus (2) according to claim 1, wherein at least one of the first and second bearing surfaces (24.1, 24.2) is annular. The percussion apparatus (2) according to claim 1 or 2, wherein at least one of the first and second abutment surfaces (22, 23) is annular. A percussion apparatus (2) as claimed in any one of claims 1 to 3, which further comprises at least one holding member (17, 28) configured to hold the second guide member (12) in the second portion of body (3.2). A percussion apparatus (2) according to any one of claims 1 to 4, wherein the mounting portion (8) of the tool (7) and at least one of the first and second guide members (11). , 12) are configured to rotatably immobilize the mounting portion (8) relative to its second body portion (3.2). The percussion apparatus (2) according to any one of claims 1 to 5, which further comprises a striking chamber (35) delimited at least in part by the striking piston (6) and the mounting portion (8). ) of the tool (7) and configured to be pressurized, and a sealing member (34) configured to seal the striking chamber (35). The percussion apparatus (2) according to claim 6, wherein the sealing member (34) is disposed between the second body portion (3.2) and the mounting portion (8) of the tool.